A turn-off-on near-infrared photoluminescence sensor for sequential detection of Fe3+ and ascorbic acid based on glutathione-capped gold nanoclusters

Many reports have suggested that near-infrared (NIR) fluorescent probes are one of the most promising molecules for improving the sensitivity of fluorescence sensing and imaging. Herein, gold nanoclusters with excellent near-infrared photoluminescence (PL) were synthesized by a simply hydrothermal treatment of hydrogen tetrachloroaurate(III) trihydrate and glutathione (GSH). The NIR PL of GSH-capped gold nanoclusters (GSH-AuNCs) can be significantly quenched by Fe3+, which follows a dynamic quenching mechanism. However, the NIR PL of the GSH-AuNCs/Fe3+ system can be recovered after the addition of ascorbic acid (AA). The decrease and increase of NIR PL intensities of GSH-AuNCs were linearly correlated with the concentration of Fe3+ and AA, respectively. Therefore, a turn-off-on NIR PL sensing strategy can be constructed for sequential detection of Fe3+ and AA with the linear range of 0.7-180 mu M and 0.5-120 mu M, respectively. The proposed NIR PL sensor exhibits excellent sensing performance and has been applied to the determination of Fe3+ and AA in real samples with satisfactory results. (C) 2020 Elsevier B.V. All rights reserved.

Automated summary

Many reports indicate that near-infrared (NIR) fluorescent probes are promising for enhancing fluorescence sensing and imaging sensitivity. In this study, gold nanoclusters with excellent NIR photoluminescence (PL) were synthesized, and a turn-off-on NIR PL sensing strategy for sequential detection of Fe3+ and AA was successfully constructed. The NIR PL sensor showed great sensing performance and was used for the determination of Fe3+ and AA in real samples with satisfactory results.